Means for operating an electric switch at a predetermined time



Feb. 28, 1950 H. WARD 2,499,046

MEANS FOR OPERATiNG AN ELECTRIC SWITCH AT A PRE-DETERMINED TIME Filed Aug. 17, 1944 Harms "W3.-

BY MM ATTORNEY.

Patented Feb. 28, 1950 MEANS FOR OPERATING AN ELECTRIC SWITCH AT A PREDETERMINED TIME Harris Ward, Burntwood, near Lichfield, England Application August 17, 1944, Serial No. 549,843 In Great Britain September 5, 1943 5 Claims.

the opposing force and permitting sudden return movement of the said member under the action of the opposing force at a predetermined time and means associated with the said member for effecting momentary closing (i. e. a make followed immediately by the break) of an electric circuit by the use of energy released during the said return movement.

The momentary current thus produced may be used to operate directly or indirectly any desired electrical appliance operable by such means.

In view of the momentary closure of the circuit the said appliance may be operated at any time independently of the mechanism forming the subject of the present invention except for the very brief period during which the momentary circuit is closed without interference therefrom.

Moreover, if the manually adjustable means remains set in one position the momentary closure of the circuit will be automatically effected under the influence of the operation of the clockwork at regular intervals with each to and fro movement of the resilient or loaded member. The invention may thus be adapted to eiiect automatically the momentary closure of a circuit at a predetermined time and at regular intervals thereafter.

Reference may be had to the accompanying diagrams in which Figs. 1 and 2 illustrate in front and side elevation one embodiment of the invention.

Figs. 3, 4, and 5 depict alternative forms of switch.

Figures 6 and 7 illustrating an arrangement in which separate hour and minute settings may be made.

In one convenient embodiment of the invention as illustrated in Figs. 1 and 2, a pendulum l insulated from the clock mechanism by an insulating support 2 is so arranged that its bob 3 normally rests against the outer face of the Lil) fiat blade spring 4. 5 is a shaft manually adjustable in an angular direction. 6 is an abutment in the form of a cross pin fixed thereto. 1 is an endwise movable wheel and 8 is a face cam rotatable with wheel 1 with which the cross pin co-operates, the arrangement of the parts 4, 5, 6, T and 8 being similar to that found in an ordinary spring-driven alarm clock.

When the mechanism of the clock operates the energising of the blade spring is effected gradually by the inter-action of the pin and cam when its wheel is rotated by the clockwork mechanism, and the instant at which release of the spring occurs is determined by the setting of the pin relative to the cam. At that instant the cross pin allows the cam wheel to move to the left suddenly under the action of the blade spring, and in so doing the upper end of the spring gives a sharp impulse to the bob of the pivoted member or pendulum I which normally rests against the blade spring.

The pivoted member is projected sharply in a direction away from the blade spring 4 and makes contact with a metal conductor 9 which may be insulated from the clock mechanism by means of a support in of insulating material or not as desired. An electric circuit including the two contacts is thereby closed momentarily. The pivoted member I then rebounds, breaking the circuit, and comes to rest against the blade sprin 4.

The current travels from the terminal ll connected electrically to the insulated pendulum, through the pendulum, and through the metal Y conductor 9 and its terminal l2 during the period of contact of pendulum and conductor. The circuit thus closed may carry a small current to act on a tripped electric magnetic (relay) switch which in turn closes a second circuit carrying the ordinary household supply in which may be included an electrical appliance such as a radio receiver electric light or alarm bell.

The setting of the time at which the switch is to operate is effected by setting the pin 6 on the shaft 5 to the appropriate position as in the ordinary alarm clock. Switch off of the second circuit above mentioned is efiected either mechanically by a push button or electrically. (As the first circuit is closed momentarily, the second circuit may be influenced at any time in- 3 dependently of the time switch mechanism except for the very brief period during which the first circuit is closed.)

Various modifications may be made without departing from the ambit of the invention some of which will now be described. In lieu of a fiat spring as illustrated, a coil spring may be fitted to operate through a metal washer against the end face of the Wheel 1. The washer may be fitted with a guide to steady it in position and with a projecting arm to support the pendulum bob.

Figs. 3 and 4 show other forms of switch operable by the pivoted pendulous member I.

Referring to Fig. 3 the pivot pin of the part I is furnished with an insulatin disc 2! having a metal contact segment 22. An insulated brush or spring 23 presses on the disc periphery so that contact is made with the segment when the pendulum is actuated as above described and broken when the pendulum rebounds.

In the modification shown in Fig. 4 a mercury switch is embodied, a sealed glass tube 24 being so connected to the pendulum as to be tilted from the position shown when the pendulum is propelled by the spring, the two contacts 25, 26, being electrically connected by the enclosed mercury 27 during the momentary period of contact. Alternatively, a mercury switch may be mounted directly on the free end of the blade spring as shown in Figure 5, the switch being connected by flexible leads to terminals on the clock structure. In each case, the mercury receives a sudden impulse causing it to move abruptly to and fro to efiect a momentary closure of the circuit.

For hour and minute settings, an hour wheel 18 and a minute wheel 1, Figures 6 and 7, are

geared to the intermediate wheel [9 of the hand train of the clock, the wheel l8 revolving once every 24 hours, and the wheel 1 once every hour, each of the wheels l8, 1 having its own spring, cam, cross pin and angularly adjustable shaft.

,Two separate dials may be incorporated for cooperation respectively with separate hour alarm hand and minute alarm hand, or if desired the two hands may be superimposed and connected by gearing to co -act with a single dial. To the hour alarm wheelis fitted a metal segment extending up to 30 (or other angle according to the contact period required) of the circle which takes up to one hour of time to move under the with the cross pin which contact lasts just under one hour (as shown) at the end of which contact is broken either by the pin riding over the insulating material of the disc or on the cam face with one end in air. In the latter arrangement, there is a rapid break when the cross pin trips off the end of the segment on to the cam rim under the pressure of the alarm spring, the wheel and cam moving endwise in two stages or steps, one for the make and one for the break.

At the set hour, the cross pin 2| rides on to the on position of the hour alarm wheel disc, and at the set minute, the minute cam 8 brings about the operation of the pendulum switch as already described and momentarily closes the primary circuit. Current travels through the insulated brush or spring 23 resting on the hour alarm wheel disc, through the cross pin 2! during its on position, through the clock work to the metal contact which is in circuit with the clock work, and through the insulated pendulum during the momentary making of the circuit with the conductor 9 to the terminal electrically connected to the pendulum.

To switch oif the secondary circuit, another wheel or pair of wheels each with cam and cross pin may be wired in that circuit.

For switching on and off at a plurality of predetermined periods, additional wheels each with its cam, cross pin and angularly adjustable shaft may be geared to and driven from one of the rotary shafts, each pair being wired in parallel with other pairs and acting independently thereof.

The contact supports or the contacting members themselves, except in the mercury switch modifications, may be of resilient character to provide rubbing contact.

Having thus described my invention, what I claim is:

1. Apparatus for operating an electric switch at a predetermined time including a clockwork mechanism, a shaft manually adjustable in an angular direction for setting the time of operation, a tripping device, a cam rotatable relative to the tripping device, resilient means normally urging said cam against said tripping device and adapted to be moved to store energy upon rota tion of said cam in one direction, an electric circuit including a movable contact normally resting against said resilient means but freely movable relative thereto so that when the cam member is released by said tripping device the resilient means returns to its original position thereby releasing the stored energy, the return movement of said resilient means effecting the movement of the movable contact to momentarily complete a circuit.

2. An apparatus as claimed in claim 1 wherein the movable contact comprises a pendulum including a bob, and a lever, the bob of which normally rests against the resilient means.

3. An apparatus as claimed in claim 1 wherein the circuit includes a fixed contact and wherein the movable contact comprises an insulating disc having a contact segment on the periphery thereof and an arm projecting outwardly from the periphery thereof which arm normally engages the resilient means whereby release of the energy stored in the resilient means effects pivoting of the disc and engagement of the contact segment with the fixed contact to momentarily complete the circuit.

4. An apparatus for operating an electric switch at a predetermined time including a shaft manually adjustable in an angular direction for setting the time of operation, a tripping device associated with said shaft, a cam member rotatable relative to said tripping device, a spring loaded member disposed to urge said cam member against said tripping device and electric contact parts including a pivotally supported mercury switch, and an arm normally engaging said spring loaded member so that when the cam member is released the spring loaded member is moved, thereby moving the said arm and momentarily changing the angularity of the mercury switch to momentarily complete the circuit therethrough.

5. Apparatus for operating an electric switch at a predetermined time including a clockwork mechanism, a shaft manually adjustable inan angular direction for setting the time of operation, a tripping device, a cam rotatable relative to the tripping device, resilient means normally urging said cam against said tripping device and adapted to be moved to store energy upon rotation of said cam in one direction, an electric circuit including a movable contact normally resting in operative association with said resilient means but freely movable relative thereto so that when the cam member is released by said 10 tripping device the resilient means returns to its original position thereby releasing the stored energy, the return movement of said resilient means effecting the movement of the movable contact to momentarily complete a circuit.

HARRIS WARD.

6 REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 480,369 Linville Aug. 9, 1892 703,033 Wright June 24, 1902 944,802 Mann Dec. 28, 1909 1,217,618 Mechau Feb. 27, 1917 1,951,027 Lux Mar. 13, 1934 

